An example of a mobile terminal capable of being operated by a touch panel is disclosed in Patent Literature 1. In a mobile terminal in Patent Literature 1, a grasped position can be determined by sensors provided on left and right side surfaces and a rear surface, and a displaying area for a key to be displayed on a touch-display is decided in accordance with the grasped position that is determined.
Furthermore, in a mobile phone in Patent Literature 2, a plurality of keys are displayed on an inputting/displaying portion composed of a touch panel and an LCD, and a user can input information by depressing a portion corresponding to a specific key.    Patent Literature 1: Japanese Patent Application Laying-open No. 2010-154090 [H04N 1/00]    Patent Literature 2: Japanese Patent Application Laying-open No. 2001-45124 [H04M 1/02, G06G 1/16]